Table 1.
Characteristics of participants enrolled in this study in the whole dataset.
| Characteristic | Total Cohort (n = 1381) |
|---|---|
| Gender | |
| Female | 707 (51%) |
| Male | 674 (49%) |
| Age | |
| 18 to 39 | 458 (33%) |
| 40 to 59 | 493 (36%) |
| 60 or older | 430 (31%) |
| Ethnicity | |
| Mexican American | 246 (18%) |
| Other Hispanic | 143 (10%) |
| White Non-Hispanic | 732 (53%) |
| Black Non-Hispanic | 205 (15%) |
| Other | 55 (4%) |
| Smoking intensity, total cigarettes over lifetime | |
| 0 | 688 (53%) |
| 1 to 50,400 | 252 (19%) |
| >50,400 | 364 (28%) |
| BMI, kg/m² | |
| <25 | 394 (29%) |
| 25 to 29.9 | 460 (33%) |
| >29.9 | 527 (38%) |
| Blood pressure status | |
| Normotensive | 659 (48%) |
| Elevated | 255 (18%) |
| Hypertension 1 | 246 (18%) |
| Hypertension 2 | 221 (16%) |
| Diabetes | |
| Yes | 133 (10%) |
| No | 1212 (88%) |
| Borderline | 33 (2%) |
| eGFR, mL/min/1.73 cm² | |
| >90 | 902 (65%) |
| 60 to 90 | 395 (29%) |
| <60 | 84 (6%) |
| Physical activity, MET-hours/week | |
| 0 | 373 (27%) |
| >0 to 4 | 93 (7%) |
| >4 to 40 | 496 (36%) |
| >40 | 419 (30%) |
| Paraxanthine/caffeine ratio | 0.15 (0.07, 0.30) |
| 1-methyluric acid/caffeine ratio | 0.59 (0.33, 1.07) |
| Bicarbonate level, mmol/L | 26 (24, 27) |
| Phosphorus level, mmol/L | 26 (24, 27) |
Categorical variables are presented as n, % (column %), based on known values; continuous variables are presented as median and interquartile range. Caffeine metabolite indices were multiplied by 1000. List of abbreviations: SD: standard deviation, BMI: body mass index, eGFR: estimated glomerular filtration rate, MET: metabolic equivalent.